The present invention relates to a stator of an. AC generator for use in a vehicle or the like. Specifically, the invention relates to a stator of an AC generator including a stator core which is constructed by helically winding at least one winding core element so as to laminate.
Referring to FIG. 4, there is shown a sectional view of a part of a stator core of a conventional AC generator. In FIG. 4, a stator core 1 is constructed by means that at least one winding core member is helically wound so as to laminate itself. Each middle portion in the height direction of tooth portions 4 of the stator core 1 has parallel edges and an equal width. Semi-closed slots 5 among the tooth portions 4 have a tapered width which is smaller in the opening side thereof. Slot insulators 6 and a stator coil 7 which include insulation conductors 8 disposed in the linear portion thereof are inserted into the slots 5, respectively. Wedges 9 are driven into the opening positioned in the slots 5, respectively.
In FIG. 6, the winding core member is shown a shape thereof before winding for constructing the stator core 1. Two winding core members 3 are punched out in a belt shape from a belt-shaped core plate 2 (for example, a silicon steel plate). The tooth portion 4 is formed in such a manner that the middle portions thereof are equal in width and parallel to each other, and each top end portion of the tooth portion 4 is larger in width than the middle portion thereof. A punched-out hole 3a is located between the two tooth portions 4.
Thus, punched-out winding core members 3 are helically wound and laminated thereof so that the top end surfaces of the tooth portions 4 form an inside circle, by use of a producing device so as to construct the stator core 1 which is shown in FIG. 4.
In FIG. 4, due to the fact that the slot 5 has the tapered shape width which is smaller in the opening side thereof, if the insulation conductors 8 are inserted one by one from the opening in the slot 5, then it becomes hard to settle the insulation conductors 8 in the opening side of the slot 5. For this reason, it is difficult to drive the wedge 9 into the slot opening.
In view of the above-mentioned circumstances, as shown in FIG. 5, the top end of a pressing member (not shown) is inserted from the opening of the slot 5 and is then struck with a hammer to thereby push the insulation conductors 8 in the slot 5, before the wedge 9 is driven into the slot opening.
As the above-mentioned stator core of the conventional AC generator, the slot has the tapered width in which the opening side thereof becomes small gradually in width, therefore, it is difficult to settle the insulation conductor 8 of the stator coil 7 in the slot 5. Due to this, there is problems that a slot insulation may receive a damage by means of a strong pressure which is supplied to the insulation conductor 8 for inserting and settling the insulation conductor 8 in the slot 5, and also an efficiency of the producing operation for the AC generator is reduced.